.box1{
    width: 100px;
    height: 100px;
    background: url(../imgs/3.png) no-repeat;
    background-size: 100% 100%;
}

.box2{
    width: 100px;
    height: 100px;
    background: url(../imgs/2.png) no-repeat;
    background-size: 100% 100%;
}

.box3{
    width: 100px;
    height: 100px;
    background: url(../imgs/1.png) no-repeat;
    background-size: 100% 100%;
}
